There is known HDMI (High Definition Multimedia Interface) Specification, as a multimedia interface between a video transmitter such as a DVD player or a set-top box and a video receiver such as a TV set or a monitor. A device having an HDMI output terminal is called source device, whereas a device having an HDMI input terminal is called sink device. For example, the video transmitter is a source device, whereas the video receiver is a sink device. And, a device having both an HDMI input terminal and an HDMI output terminal to function as both of a source device and a sink device is called repeater device.
An HDMI communication device for performing communication according to the HDMI Specification has: a TMDS (Transition Minimized Differential Signaling) transmission module which transmits video, audio and auxiliary information; a +5V power supply signal transmission module for informing a sink device or a repeater device of connection in the form of a source ready signal when a source device is connected to the sink device or the repeater device; an HPD (Hot Plug Detect) signal transmission module which transmits an HPD signal as a sink ready signal indicating that the sink device or the repeater device is ready for receiving video information; an EDID (Extended Display Identification Data) transmission module which transmits EDID which are data such as product information of the connected sink device and an adequate video format; an HDCP (High-bandwidth Digital Content Protection) authentication module which authenticates the sink device; and a CEC (Consumer Electronics Control) transmission module which transmits CEC including a device control signal and a control protocol.
There is a recently increasing demand for high-definition video of 3840×2160 called 4K2K. However, in transmission of such high quality video, the load imposed on a communication interface will increase.